This invention is generally directed to the field of preparation of vegetable such as potatoes, plantains and the like prior to frying, baking or drying and more specifically relates to slicing a vegetable product to the desired thickness and simultaneously washing the sliced vegetable for removal of starch, ruptured cells and the like.
In the process for the preparation of potato chips, for example, it is commonly found that the potatoes are first treated to the gross removal of dirt from the whole potatoes. Then the potatoes may undergo skin removal in a peeler, although this is not always the case, and are then forwarded to a slicer which cuts the potatoes to the desired thickness, usually on the order of 0.60 inches thickness. In the slicing operation the potato body is penetrated by a metal blade which ruptures the vegetable cells and leaves a residue or film of starch and broken cells dispersed over the surfaces of the slices. The presence of the film is undesirable in subsequent processing steps such as frying or baking although for certain chip styles the presence of the film of starch is tolerated. However, washing the slices in a water bath is the common practical method of cleaning the starch and ruptured cell film from the slices. In that step, the slices are deposited into the water bath either directly from the slicer or from a conveyor belt which carries the slices from the slicer outlet located remotely from the bath. The bath for washing the slices may have agitation supplied therein to promote a vigorous action of the water upon the surfaces of the slices to achieve effective removal of the starch film. The washed slices were removed from the bath typically upon an inclined conveyor and when removed from the water may then be subjected to water sprays and/or an air blast to remove residual starch particles and water film from the surfaces of the slices. Thus prepared, the potato slices are advanced to additional processing steps leading toward the desired finished products, usually fully cooked chips.
French-fried potatoes in their preparatory processing steps undergo a step of cutting the whole potatoes into strips generally sized to resemble the finished fried product. A successful method of potato strip cutting has been to propel, such as by pumping, the potatoes in a fast-moving charge of water against and through a fixed, crisscross array of knives or other potato cutters. This splits the potatoes into strips in the presence of water employed to drive the vegetables through the knives or other cutters. See U.S. Pat. No. 5,042,342 to Julian assigned to Lamb-Weston, Inc. of Kennewick, Wash.; U.S. Pat. No. 5,168,784 to Foster et. al assigned to Universal Frozen Foods, Inc. of Twin Falls, Id.; and U.S. Pat. No. 5,179,881 to Frey et. al. assigned to McCain Foods Ltd. of Florenceville, Canada.
One important objective of this invention is to eliminate the separate washing step following slicing in vegetable processing through combining the slicing and washing step for efficient removal of starch film from the sliced pieces.
In summary the invention resides in a process of simultaneously washing and slicing a raw vegetable such as potatoes, apples, sweet potatoes, cassava, plantains, beets, onions, water chestnuts, carrots, turnips, cabbage and sugar beets and the like, the process including the steps of providing a flume or vat of washing water equipped with an inclined takeout conveyor positioned with its lower end submerged in the water and its upper end extending above the water surface, positioning a vegetable slicer with its product reception inlet above the water surface and its slice discharge outlet positioned below the water surface. The vegetables are supplied to the slicer inlet as it is operating so that the slices are discharged underwater serving to directly and forcefully clean the slice surfaces of dirt, starch and burst cells. The water is circulated in a current at a force such that the slices are urged toward or attracted to and dispersed upon the conveyor which is operated to remove the slices from the wash water for further processing.
An object of the invention is to provide an improved process for the preliminary preparation of slice-able vegetables wherein the washing and slicing steps may be undertaken simultaneously thereby effect a savings in processing time and equipment expense.
Another object of the invention is to provide an efficient combined processing step of slicing, washing and dispersing the washed slices on a takeout conveyor in an arrangement which minimizes slice overlap thereby reducing the tendency to form clumps of the sliced product in subsequent cooking including frying steps.
Yet another object of the invention is to provide for the substantially complete removal of slices from the slice washing bath irrespective of the vortexes or turbulence therein.
Still another object of the invention is to provide a process for economical slicing and washing of potatoes preparatory to frying which is efficient in the use of equipment and time and is labor saving.
Additional objects and features of the invention will be readily understood and appear below in the drawings and description of preferred embodiments of our invention.